Electrical apparatus



Feb. 5, 1946. B. o. AUSTIN ,393,

ELECTRICAL APPARATUS Filed Jan. 12, 1944 WITNESSES: I INVENTOR @441 I Bascum 0. Aus tin.

Patented Feb. 5, 1946 ELECTRICAL APPARATUS Basoum 0. Austin. Lima, Ohio, assignor to Westinghonse Electric Corporation, East Pittsburgh, 2a., a corporation of Pennsylvania Application January 12, 1844, SerlalNo. 517,815

.20laims.

, This invention relates to electrical apparatus and, in particular, to regulators of the pile type.

An object of this invention is to provide a lightweight regulator of the pile type which is stable in operation.

Another object of this invention is to provide for suppressing arcing between the disks of a pile regulator while at the same time providing for an eillcient dissipation of heat therefrom.

A more specific object of this invention is to provide for sealing the movable parts of a pile regulator in a thermally conducting electrically insulating liquid medium to decrease the friction of such moving parts while simultaneously therewith eflectively reducing arcing and increasing the dissipation of heat and thereby increasing the icapacity of the regulator without an increase n s ze.

Other objects of this invention will become apparent from the following description when taken in conjunction with the accompanying drawing, the single figure of which is a view in elevation and partly in section of a regulator embodying the teachings of this invention.

Referring to the drawing, this invention is illustrated by reference to the regulator l8 shown therein. The regulator I8 is of the pile type having a stack l2 of aligned disks l4 of high resistance material such as carbon or the like mounted in a sectionalized housing or casing i8 and disposed to be operated by an electromagnet l8. The casing I8 is formed of a plurality of sections, an end or base section 28 being connected to an end cap 22 by an intermediate constricted section 24.

The stack I2 of disks i4 of high resistance material is assembled in operative relation on a shaft on rod 28 of insulating material such as a ceramic rod the rod 28 extending through openings 28 positioned centrally in each of the disks for maintaining the disks in aligned relation. One end of the rod 28 is supported in a sleeve 88 of conducting material, the sleeve 88 being secured to a ring 82 of conducting material as by means of the flared end 84 and the shoulder 88 carried at one end of the sleeve for forming a recess into which the ring 82 is fitted. The ring 82 is, in turn, secured to the end of the end cap 22 by means of a. plurality of screws 88 disposed in-spaced relation about the sleeve 88. the screws 88 being insulated from the ring 82 of conducting material by means of the insulating bushings 48 and washers 42. The ring 82 is also insulated from the end cap 22 by means of a sheet 44 of insulating material such as ilshpaper or the like. In order to provide an electrical connection external of the housing or casing it, the ring 82 of conducting material carries a projection 48 for receiving a screw 48 which is utilized for connecting one end of a conductor 88 to the ring, the other end of the conductor being secured to a conducting bolt 82 which extends through the side wall of the end cap 22, insulating washers 84, and an insulating bushing 88 being provided for insulating the bolt 82 fromthe end cap 22. As illustrated, a pressure plate 88 is disposed between the other flanged end of the conducting sleeve 38 and the end of the stack l2 of disks i4 for distributing pressure over the face of the end disk.

The other end of the rod 28 projects from the other end of the stack l2, a pressure plate 88 being disposed about the shaft 28 adjacent the end .of the stack l2- and a sleeve 82 being positioned about the rod 28 and having a flanged end for seating against the pressure plate 88. The sleeve 82 is similar to the sleeve 38, being provided with a" shoulder 84 and a flared outer end 88 for holding a ring 88 of conducting material. The ring 88 is similar to the ring 82 at the opposite end of the staclr having a projection 18 for receiving a screw 12 for securing one end of a conductor- 14 thereto. The other end of the-conductor 14 is secured to the bolt 18 which projects through but is insulated from the section 28 of the casing in a manner similar to the bolt 82.

As illustrated, the section 28 of the housing or casing [8 has an inwardly projecting partition 18 disposed about its periphery approximately midway of the length of the section. On one side of the partition 18, a ring 88 of stainless steel or the like having a sloping or beveled surface 82 is disposed to seat against the outer walls of the section 28 and the partition I8. The ring 88 is of such a .size that an armature member 84 may be fitted within the inner diameter of the ring.

The armature'member 84 utilized in the regulator i8 is substantially a disk and is carried by the ring 88 which is secured to the sleeve 82. The armature member 84 is preferably faced on one side thereof by a sheet or layer of insulating material 88 which functions to electrically separate the armature member 84 and a spring member 88. The spring member 88 illustrated is a leaf spring and may be of star-shape or a circular disk, the ends or outer periphery of which are bent to seat against the sloped surface 82 of. the ring 88, the purpose of which will be described more fully hereinafter. In order to hold the spring 88 in the position described, a reinforcing sheet 80 of metal or the like is placed adjacent the surface of the spring 88 opposite the surface in contact with the sheet 08 of insulating material, and a layer 82 of insulating material is then placed against the supporting sheet 80. This assembly of the insulating sheet 82, reinforcing plate 80, spring member 88, insulation 86, and the armature member 84 is held together as an integral unit by means of the screw 84 and is mounted as an integral unit on the ring 88 by means of the screw 86, the screw 86 being insulated from the ring 88.

As illustrated, a winding'88 having leads 81 and 88 is positioned on the other side of the partition 18 of the section 20 and disposed to be encased in the housing I8. However, before the winding 88 is positioned in the casing I8, a ring I of brass or similar non-magnetic material is secured about the inner circumference of the partition I8 as by brazing, as shown at I02, and a metallic sleeve I04 provided with threads on its inner surface is secured to the inner circumference of the brass ring I00 as by brazing at I08, as illustrated. In positioning the winding 88 in the housing, the winding preferably mounted on a spool I08 of insulating material is slipped over the end of the sleeve I04 to a position where the side wall of the insulating spool I08 seats against the partition 18 and the brass ring I00 and the leads 81 and 98 project through suitable openings in the casing. In this position, an end cap or plate IIO may be secured to the ends of the section 20 of the housing by the bolts II2 which are disposed in spaced relation about the periphery of the end plate H0. The end plate IIO seating against the winding 98 maintains the winding in position about the sleeve I04 and prevents movement of the winding.

With the winding 88 assembled as described, a core member II4 have an externally threaded surface is threaded into the threaded sleeve I04 to a position where the end of the core member H4 is spaced a predetermined distance from the armature member 84. By adjusting the position of the core member II4, a predetermined position of the core member may be obtained where a required balance between the magnetic pull and the force of the spring member 88 is obtained over an operating range of the regulator. This position of the core member II4 will necessarily depend upon the strength of the spring member 88 which is positioned to apply pressure to the stack I2 and the slope of the sloped surface 82 of the ring member 80, it being noted that as the armature member is moved under the influence of the magnetic pull that the effective arm length of the spring member 88 changes since more and more of the spring 88 engages the sloped surface 82 of the ring 80. When the core member H4 is thus adjusted to obtain the required gap between the armature member and the core member, the external end of the sleeve I04 and the core H4 is brazed as at II8 for sealing the threaded joint between the two members. The threaded Joints between the end cap 22 and the constricted section 24 is likewise brazed as at H8, and the threaded Joint between the constricted section and the end section 20 of the casing is also brazed as at I20 to provide a sealed casing about the movable elements of the regulator I0.

As will be noted, the constricted section 24 of the casing is of a size determined by the size of the stack I2 utilized in the regulator. Preferably the constricted length of the section 24 has a diameter only slightly greater than that of the stack of disks, spacing being provided. however. for the positioning of a sleeve I22 of insulating material such as porcelain, the sleeve I22 being spaced slightly from the stack I2. As illustrated, the sleeve I22 of porcelain is maintained in position by brazing ring members I24 and I28 to the constricted section 24 at opposite ends of the sleeve I22.

In order to effectively aid in dissipating any heat that may be generated in the stack I2 of disks I4, a plurality of radiating fins I28 are disposed about the constricted section 24 of the easing, the fins I28 preferably being formed of aluminum or the like and being formed on a sleeve I which fits about the constricted area. The sleeve and fin assembly may be formed in two half sections which when placed about the constricted section 24 may be bolted together to form a continuous radiating assembly about the constricted section 24.

As illustrated, the end cap 22 is also provided with a vent I40 which may be sealed. After the regulator is assembled, the housing or casing I0 is preferably evacuated, suitable vacuum equipment (not shown) being attached to the vent I48 for accomplishing this purpose, and when evacuated, a thermally conducting electrically insulating liquid medium I 42 is admitted to the housing. Preferably the liquid medium admitted to the housing or casing I8 is a permanentl liquid dialkyl silicone. 0f the known silicones, that silicone liquid which is essentially dimethyl silicone which has been polymerized and is free of mono-methyl silicone groups is preferred, The essentially dimethyl silicones are produced by fractionating a mixture of methyl silicon ethoxides to separate the dimethyl silicon diethoxide as a substantially pure component which is hydrolyzed to the dimethyl siiicol and then dehydrated with an agent such as sulphuric acid to dimethyl silicones of predetermined molecular size, By fractionating the oily dimethyl silicones, a stable liquid of predetermined viscosity may be obtained. This process and product is described in greater detail in the copending application of J. G. Ford and R. N. Wenzel, Serial No. 439,066, filed April 15, 1942, and assigned to the assignee of this invention. The dimethyl silicone insulating medium is especially suited for use in the regulator of this invention as it is especially stable over wide ranges of temperature, very little change in viscosity being encountered over ranges of from 70 F. up to as high as 500 F.

After the liquid medium I42 is admitted to the housing I8, a cap I44 is placed upon the vent I40 and the Joint is brazed or soldered as at I48 for effectively sealing the vent. 'llhus all the moving elements of the regulator are enveloped in a liquid insulating medium, and the casing is sealed to prevent loss or contamination of the liquid insulating medium.

In operation, it is found that the regulator described hereinbefore is very stable, the insulating medium functioning to damp excessive movement of the movable elements. Further. as will be apparent, the insulating medium penetrates into every Joint within the sealed casing, thereby providing an efficient lubrication of all the moving elements, the reduction in friction thus obtained increasing the efficiency of the regulator,

With the insulating medium nlling the casing II as described, it is found thata very emcient I appended claims.

radiating fins I28 carried about the constricted section 24. Further, it is found that although the disks are enveloped by the insulating medium, the insulating medium in no wa interferes with the operation oithe stack H, but instead prolongs the life or the stack in that the insulating medium emcientl suppresses arcing between the carbon disks, thereby preventing the deterioration of the disks of resistance material and greatly prolonging the life of the regulator. The cushion of insulating material between the stack l2 and the sleeve I22 of porcelain or the like also functions to cushion any sideways movement of the disks l4 and thereby tends to prevent damage to the disks when the regulator is violently Jarred, as it sometimes is in such appli cations as on aircraft. By providing for eillciently dissipating the heat from the stack as described,

the capacity of the regulator is greatly increased over that of a regulator which does not utilize an insulating medium in the manner described hereinbefore without increasing the size 0! the regulator.

reference to a particular embodiment thereof, it

is, of course, not to be limited thereto except insofar as is'necessitated by the scope ot the I claim as my invention: a

1. An electric regulator comprising, in combination. a stack of disks of resistance material, a pressure plate at each end of the stack of disks, a spring member associated with one of the pressure plates disposed to apply pressure to the stack. an electromagnet comprising a winding, a

- core member and, an armature member. the

armature member being disposed to control the pressure applied to the spring member in response to the energization of the electromagnet, a casing for the stack and associated spring and armature members for housing them, the casing including the core member of the electromagnet and having sealed jointstherewith to render the casing .leakproof, the casing having a constricted section about the assembled stack, radiating fins nation, a stack of disks of resistance material, a

The regulator 01' this invention will find wide pressure plate at each end of the stack of disks,

a spring member associated with one of the pressure plates disposed to apply pressure to the stack, an eleotromagnet comprising a winding, a core member and an armature member, the armature member being disposed to control the pressure applied to the' spring member in response to the energization oi the electromagnet, a casing for the stack and associated spring and armature members for housing them, the casing including the core member oi the electromagnet and having sealed joints therewith to render the casing leakproof, the casing having a constricted section about the assembled stack, radiating fins carried in spaced relation about the constricted section or the casing, and a thermally conducting generated in the stack.

BASCUM O. AUSTIN. 

